Transposons are mobile genetic elements found in the hereditary material of humans and other organisms. They can replicate and the new copies can insert at novel sites in the genome. Because this threatens the whole organism, molecular mechanisms have evolved which can repress transposon activity. Professor Klaus Förstemann of the Gene Center of Ludwig-Maximilians-Universität (LMU) in Munich and a team of researchers working with the fruitfly Drosophila melanogaster have now uncovered a new type of cellular defence that acts against DNA sequences present in high copy numbers inside the cell, even if they have not integrated into the genome. Small molecules of RNA (a class of nucleic acid closely related to the genetic material DNA) play the central role. "Transposons are genomic parasites, so to speak", says Förstemann. "If they are allowed to proliferate, the genome can become unstable or cancers can develop. We now want to find out whether mammalian cells possess this newly discovered defence mechanism and to elucidate precisely how it works." (EMBO Journal online, 30 July 2009.)

The human eye lens consists of a highly concentrated mix of several proteins. Protective proteins prevent these proteins from aggregating and clumping. If this protective function fails, the lens blurs and the patient develops cataracts. Two research groups at the Department of Chemistry of the Technische Universitaet Muenchen (TUM) have succeeded in explaining the molecular architecture of this kind of protective protein. Their findings, which are published online in the current early edition of PNAS (Proceedings of the National Academy of Sciences), shed new light on the work of these proteins and may be able to help in the development of new treatments.

You probably hadn't noticed -- but the head shape and overall size of rodents has been changing over the past century. A University of Illinois at Chicago ecologist has tied these changes to human population density and climate change.

Researchers at the Center for Infection and Immunity (CII) at Columbia University Mailman School of Public Health are working with Argentina's National Institute of Infectious Diseases, the National Administration of Laboratories and Health Institutes (ANLIS), and Roche 454 Life Sciences to decode the complete genomic sequences of influenza pandemic (H1N1) 2009 virus from patients with severe respiratory disease. The scientists will be comparing sequences of viruses associated with the current outbreak in Argentina with those found in other locations to determine if there are differences that may be linked to higher mortality rates or provide insights into virus evolution.